Turnbuckle screw device



Dec. 17, 1957 ,1. P. ROBERTSON TURNBUCKLE SCREW DEVICE 2 Sheets-Sheet 1 Filed 1:65. 6, 1952 INVENTOR Dec. 17, 1957 1 J. P. ROBERTSON TURNBUCKLE SCREW DEVICE Filed Dec. 6, 1952 2 Sheets-Sheet 2 Egg 9 N @X m\ m z w M H mm H I w\ I m lm:

x NQ X rlll ZVl/l/IK 1 .w MW IF m 747/177 Av /A Ill. uflFEEUEE MN United States Patent 1 My invention relates broadly to multiple lift type disc harrows and more particularly to an improved construction of depth regulating means for adjusting the relative depth of cut of the gangs of discs in a multiple lift type disc harrow.

One of the objects of my invention is to provide an improved construction of precision adjustment'means for use on multiple lift type disc harrows for regulating the relative depth of cut of the gangs of discs carried by the harrow.

Another object of my invention is to-provide a construction of close tolerance adjustment strut for use on multiple lift type disc harrows for regulating the relative depth of cut of the gangs of discs carried by the harrow.

Stillanother object of my invention is to provide a construction of adjustment strut in which the strut is formed of polygonal section and extends lineally for a substantial distance allowing a grip to be applied at various positions along the strut for revolving the strut either clockwise or counterclockwise for changing the relative distance between the coupling frame of the harrow and the substantially horizontal frame of the harrow for thereby changing the relative depth of cut of the rear gangs of discs with respect to the front gangs of discs in a multiple lift type disc harrow.

Still another object of my invention is to provide a construction of adjusting strut for a multiple lift type disc harrow which includes a lineally extending member of polygonal section having rightand left-hand threaded members secured in opposite ends thereof for engagement with the correspondingly threaded fittings connected, respectively, to a coupling frame connected with a tractor and to thehorizontally extending frame of the'multiple lift type disc harrow, the said fittings having coacting jam nuts thereon enabling the fittings to be adjusted to be maintained in selected positions for selectively controlling the distance between the coupling frame and the substantially horizontally extending harrow frame for correspondingly controlling the relative depth of cut by theharrow discs.

A still further object of my invention is to provide a construction of adjustment strut for controlling the position of multiple lift type disc harrows with respect to a tractor in which replaceable rightand left-hand screwthreaded members are carried by opposite ends of the strut for coaction with correspondingly screw-threaded fittings, the replaceable screw-threaded members being renewable through the ends of the strut in the event of stripping of the screw threads therein without the necessity of replacing other components of the *strut.

A still further object of my invention is to provide an arrangement of close tolerance adjustm'entstrut having an actuating tubular-sleeve-of substantially rectangular cross- "section with an operating handle extend'ing transversely therethrough and forming means for revolving the strut for correspondingly turningrig'htand left-hand screwthreaded members carried-in theatres thereot'andaetin 2 upon correspondingly screw-threaded fittings displaceable upon a lineal axis to-the strut.

Other and further objects of my invention reside in the construction of close tolerance adjustment strut described in the specification hereinafter following by reference to the accompanying drawings, in which:

Figure 1 is a sideelevational view of a multiple lift type 'disc harrowshowing the adjustment strut of my invention in positionthereon for maintaining the front and rear gangs of discs at such a level that the depth of cut of the several gangs of discs is substantially uniform; Fig. 2 is a vertical sectionalview taken substantially on line 2 --2 of Fig. 1; Fig.3 isa vertical sectional view taken substantially on line 3"--3of Fig. 1; Fig. 4 shows the adjustment strut of my'i'nvention adjusted to a position for controlling the depth of cut'of the rear gangs of discs relative to the depth of cut of the front gangs of discs; Fig. 5 is a side elevational 'v'iewof the adjustment strut of my invention, the View being longitudinally foreshortened; Fig. 6 is a plan viewbfthe strut, th'e'view being partially broken away arid S'h'OW-ll sectionand the view'being foreshortened in 'a rriafineirs'ir'nila'r to the view illustrated in Fig. 5; Fig. 7

is a longitudinal transverse sectional view through the tion; Fig. 11 is a transverse sectional view taken on line 11--11 of Fig. 10; Fig. 12 is a transverse sectional View taken on line 1212 of Fig. 10; and Fig. 13 illustrates one form of means for removing the left or right screwthreaded member from the end of the strut in the modified form of my invention shown in Figs. 10-12 in the event of stripping or injury to the threads in the ends of the strut.

My invention is directed to precision adjustment means for controlling the depth of cut of rear sets of gangs of discs with respect to the front sets of gangs of discs in a multiple lift type disc harrow. I provide a lineally extending strut of tubular form which is substantially polygo-nal in section and which supports rightand left-hand screw-threaded means in opposite ends thereof for receiving correspondingly screw-threaded fittings, one of which attaches to a suspension frame which couples to a tractor and the other of which connects to a central position adjacent the trailing edge of the front frame. The shape of the strut is such that it may be readily engaged manually or engaged by a wrench at any position along the length thereof and revolved to control the angular relation of the frame of the harrow to the suspension frame for correspondingly regulating the depth of cut. I provide an arrangement of jam nuts for maintaining the fittings in a selected adjusted position with respect to the strut. I so construct the rightand left-hand screwthreaded members and mount them in the opposite ends of the tubular strut in such manner that the r'ightand left-hand screw-threaded members, if stripped or otherwise injured, may be readily replaced without replacing all of the component parts of the strut.

Referring to the drawings in more detail, reference character 1 designates the front frame of a multiple folding lift type disc harrow which pivotally connects at its front end with the vertically extending suspension frame 2 pivoted at 3 to the frame 1. The suspension frame 2 connects the links 4 and 5 with a tractor. The front frame 1 carries the revolvable gangs of discs represented at 6 The trailing edge of the front frame 1 is provided with connecting means represented at 7 'in which the screw-threaded fitting represented at '8is mounted for anguiar-meve'ment." "The ttailin'g edgeof thefront rame 1 is also provided with hinge members represented at 9 which coact with hinge members represented at 10 arranged on the leading edge of the rear harrow frame 11. There are depending members 12 carried by the trailing edge of front frame 1 in alignment with depending members 14 carried by the leading edge of rear frame 11 which may be interconnected by bolt members 15 for maintaining the rear frame member 11 in coplanar alignment with the front frame 1. The rear frame 11 carries gangs of harrow discs 16. Rear frame member 11 may be divided into sections and the sections individually moved to a position Over front frame 1 guided by the hinge members 10 upon removal of fastening bolts 15.,

The adjustable strut of my invention is shown more particularly in Figs. -13 and includes the screw-threaded fitting 8 adjustable through one end of the strut and the screw-threaded fitting 18 adjustable through the other end of the strut. The screw-threaded fittings 8 and 18 are both provided with T-shaped termini shown at 8a and 18a for respectively engaging the connecting means 7 on the trailing edge of front frame 1 and the transverse connecting means 19 on the suspension frame 2. The screw-threaded fitting 18 is angularly shiftable with respect to transverse connecting means 19. Screw-threaded fitting 8 carries left-hand threads represented at 8b while screw-threaded fitting 18 carries right-hand threads represented at 18b. These leftand right-hand threads engage correspondingly screw-threaded inserts represented at 20 and 21 of polygonal contour and which fit within the tubular strut 22 of corresponding contour. The screwthreaded fittings 8 and 18 each carry jam nuts 23 and 24 thereon which bear against the ends of the screwthreaded inserts 20 and 21 which terminate coplanar with the opposite ends of the tubular strut 22.

The tubular strut 22 is polygonal in section so that it may be manually grasped or engaged by a tool at any position intermediate its opposite ends and revolved for adjusting the distance between the fittings 8 and 18 and correspondingly adjusting the distance between suspension frame 2 and the trailing edge of horizontal frame 1. To facilitate the revolving strut 22, I provide a transversely extending bar 25 projecting through the strut 22 at a position intermediate the opposite ends thereof and which may be manually grasped for rotating the tubular member 22 for projecting or contracting the fittings 8 and 18. As the fittings 8 and 18 are projected, the rear gangs of discs shown at 16 are moved downwardly as represented in Fig. 4 from the normal position represented in Fig. 1 for thereby controlling the relative depth of cut of the rear gangs of discs 16 in the earth 26 as compared to the relative positions of the gangs of discs 6 and 16 represented in Fig. 1.

The screw-threaded inserts 20 and 21 may be rectangular or square in contour and the tubular strut 22 may be correspondingly shaped. Normally the screw-threaded inserts 20 and 21 may be welded in position in the ends of the tube 22. I prefer, however, to arrange the screwthreaded inserts 20 and 21 so that they may be readily removed from opposite ends of the tubular strut and renewed in the event of the stripping of the screw threads for thus enabling the screw-threaded inserts to be replaced Without the necessity of replacing the other components of the strut. This may be accomplished by the arrangement represented in Figs. -13 wherein the in sert 21 is shown provided with diametrically opposed indentations represented at 21a into which indentations 22a may be struck from the walls of tubular member 22 for maintaining the inserts in position. In this form of my invention, the tubular member 22 is provided with diametrically opposite instruck projections 22b at a distance from opposite ends thereof equal to the length of the inserts 20 and 21 and serving as abutments for seating the inserts 2t) and 21 in positions in the ends of the tubular member 22 so that the ends of the inserts terminate coplanar with the ends of the tubular member.

When it is necessary to remove an insert having stripped threads, the arrangement shown in Fig. 13 is employed wherein a tool having a pair of arms 27 engaged against the ends of the tubular strut 22 is provided with a pair of insertable arms 28 which may be passed through the screw-threaded insert and engaged with the inner end wall thereof and then advanced outwardly under the action of screw-threaded member 29 engaged in a screwthreaded cross-head 30 connected with the arms 27. The instruck projections 22a in tubular member 22 are sprung outwardly and the defective screw-threaded insert removed. The replacement insert is forced into the open end of the tubular member 22 and clamped in position by applying pressure to the indentations 22a in the walls of the tubular member 22, whereupon the replaced insert is ready for operation without renewal of any other of the component parts of the strut.

I have secured excellent results by the use of a tubular strut formed from 2%" square tubing approximately two feet long and using screw-threaded fittings of 1%" stock having rightand left-hand threads of seven threads to the inch and coacting with 1 /3" jam nuts and operating into correspondingly screw-threaded inserts.

While I have described my invention in certain preferred embodiments, I realize that modifications may be made, and I desire that it be understood that no limitations upon my invention are intended other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A screw device comprising a tubular member of polygonal cross section having a multiplicity of flat oppositely disposed laterally spaced sides, rightand lefthand screw threaded members corresponding in cross section with the internal cross section of the opposite ends of said tubular member carried within opposite ends of said tubular member with the outermost end surfaces of said screw threaded members extending substantially coplanar with the terminating interior surfaces of the ends of said tubular member, instruck projections formed in the oppositely disposed fiat laterally spaced sides of said tubular member at positions spaced from the ends of said tubular member for lineal distances substantially equal to the length of said rightand left-hand screw threaded members and forming a multiplicity of spaced end abutments engaging the internal end surfaces of said rightand left-hand screw threaded members for preventing displacement thereof into said tubular member and maintaining the outermost end surfaces thereof coplanar with the ends of said tubular member when said tubular member is placed in compression stress tending to drive said screw threaded members into the interior of the ends of said tubular member, screw threaded adjustable attachment fittings engaged in said rightand left-hand screw threaded members and a hand operated member attached to said tubular member for imparting rotation thereto.

2. A screw device as set forth in claim 1 in which said tubular member of polygonal cross section and said rightand left-hand screw threaded members are square in cross section and wherein said instruck projections establish abutments with the internal end surfaces of said rightand left-hand screw threaded members at substantially the centers of the peripheral portions of the said rightand left-handscrew threaded members.

3. A screw device as set forth in claim 1 in which the opposite edges of said rightand left-hand screw threaded members are symmetrically recessed substantially midway of the length thereof and wherein the opposite fiat laterally spaced sides of said tubular member are indented and enter the aligned recesses in the edges of said rightand left-hand screw threaded members substantially in alignment with the instruck projections extending inwardly from the sides of said tubular member.

vA WW de ice as s t forth in claim .1 in h ch said tubular member of polygonal cross section and said References Cited in the file of this patent rightand left-hand screw threaded members are sq1 1are UNITED STATES PATENTS in cross section and wherein said mstruck PI'OJECHODS establish abutments with the internal end surfaces of said 4075 n July 1389 rightand left-hand screw threaded members at sub- 5 879'268 Jamleson 1908 stantially the centers of the peripheral portions of the 13741963 st,evenSn 1921 said rightand left-hand screw threaded members, and 1'848'242 Tldeman Man 1932 wherein the opposite edges of said rightand left-hand 1903'863 Hayden 181 1933 screw threaded members are symmetrically recessed sub- 1'971'472 Wolf 1934 stantially midway of the length thereof in alignment with 10 3352585 Cambum June 1944 said instruck projections and wherein the opposite fiat 360919 Ryan at 1944 sides of said tubular member are indented and enter the 2'658546 cmwther 1953 aligned recesses in said rightand left-hand screw threaded FOREIGN PATENTS members for locking said rightand left-hand screw 122,325 Great i i Jam 23, 1919 threaded members in the ends of said tubular member. 15 495,976 Great Britain Nov. 23, 1938 

